Canon EF 70-210 mm f/ 4 Lens

Cheap, constant f/4 aperture accross the 70-210mm focal length range, focus limiter.

Weaknesses:

Slow focus motor, some vignetting, chromatic aberration not well controlled and some softness at f/4.

Front element rotates while focusing.

Not compatible with Canon Teleconverters.

All made of plastic, only the mount is made of metal.

Comments:

To be honest, I like this push-pull design, much faster than rotating the focal-length ring on other lenses.

I also like the constant f/4 aperture accross the focal range, this is important for me when shooting indoors with an external flash (I like to use flash in manual mode). Or when shooting outdoors in Av mode and controlling the shutter speed.

To get sharp results I need to close one full stop (f/5.6), at f/4 some softness is present but pictures are usable.

This lens, IMHO, is better than the cheap Canon 75-300mm f/4-5.6 USM III, from a optical point of view.

This lens suffers from chromatic aberrations in high constrast areas, closing the aperture here doesn't helps.

The worst thing is the slow focus motor, not usable in fast outdoor sports like soccer if you get the player running to you. It also slows down the max FPS of my 50D, shotting slower than 6fps.

You cannot use Canon's teleconverters with this lens, they will not fit.

You can get nice portraits with blurred backgrounds.

Cheap, easy

Weaknesses:

Constructive, sucks dust, second-hand copies are often caught with the condensate on the inner lens. Sharpness is not used to that seen in the examples, =)

Comments:

The lens is not liked

Very compact and lightweight for this focal range. Always take to trip. Operative zoom. Perfectly sharpness of image from 5.6. At the 4 bit soft, I use mainly for portraits. A small built-in lens hood. Convenient filter diameter 58.

Weaknesses:

Glares, noise focusing, vignette at max aperture

Comments:

Compared with 70-210 / 4. I thought I'd buy it if the results are better. But in almost all apertures except 4 this lens gives a picture not conceding in quality L lens. A softness in the aperture I even like, the portraits come out softer and hide imperfections. In the end, left a 70-210. A very good lens. To quickly focused, turn off the switch Macro;)

Very good for the $ 120 spent.

Weaknesses:

Poor construction rim

Comments:

Decent picture even with an open aperture, and not inferior in my opinion the prime Canon 50mm F1, 8, jammed to the F5, 6. Fast enough, though noisy autofocus. Very comfortable and superfast push / pull system zoom.